Method and apparatus for effecting heat interchange



Aug. 12, 1930. 1 M. FoRNcRooK METHOD AND APPARATUS FOR EFFECTING HEAT INTERCHANGE Filed May 3, 1927 mesma Aug. 12.1930

iLAWRENCE u. ronNcnoo/x, or rIr'rsBURaH, rnNNsYLvANIA, Assumer. 'ro anneau*l 1' PITTSBURGH, PENNSYLVANIA, A (J0:BE'OIR'A'IIOBTv 0F PENNSYLVANIA Mn'rnon AND nrrmrus ron. Errncrme naar :Nummer:

Application led Hay 8, 1927. Serial No. 188,470.

This invention relates broadl to the art of effecting a heat interchange tween two fluids such, for example, as a gas and a liquid,-and.more A apparatus in vo ving heat exchange of the tyffpe secured 1n condensers for thepurpose of e ecting condensation of a vapor or vapors.

f It is customary in theart to which the present invention relates to effect the' condensation `of a vapor or vapors in a tubular condenser, the temperature of the condensate produced dependingupon the construction and manner of operation of the condenser. In; many cases, it is desirable to produce a 15 condensate. having a temperature materially lower than that at which condensation actually takes lace. This is particularly true in the art ci) petroleum distillation, and the present invention has.. for one of its objects the provision of a method and apparatus effective for producing a condensate having a temperature below the actual condensation temperature.

In many cases vapors resultingfrom the destructive distillation of oil must be condensed at tem eratures so -high that it would be extremely, angerous to remove and store -the Zcondensate at such temperatures due to thepossibility of trouble resulting from contact therewith of the oxygen in the air.

It is well known to those skilled in. the art permit the desiredfopera-tion thereof, there `1s provided a gas vent at the-end of the zone of condensation( Where the condenser is being operated at pressures higher than atmospheric, thevent usuall discharges directly to the atmosphere, while, in cases o f articularly to methods and in pressure conditions within and without the condenser where condensation is carried fon.l at pressures lower than atmospheric. In the usual operation ofvcondensers, this conditionj is decidedly objectionable, and in -order to Q ttal pressure represents a relatively `high partial pressure of the non-condensible gas constituent, and a relatively low partial pressure dueto the condensible or vapor constituent with a consequent lowering of the temperature conditions of the vapor.

Another object of the present invention,

therefore, is to eect an operation 'such that the partial pressure of the noncondensible eonstituentswithin the heat exchanger is increased in a controlled zone with a resulting decrease in the partial pressure of thecondensible constituents, and the consequent vapor temperature of condensible constituents such that any condensate in contact with such zone may have its temperature lowered below the temperature of condensation.

In the accompanying figure of drawmgs, there is illustrated ipartly in section and partly in elevation, an largelg diagrammatically, one form of apparatus means of which the present invention may ev carried out, 1t being understood that the drawings do not define the limits of my inventlon since changes in the construction and operation therein disclosed may be made without departing either from the spirit of the mvention or the scope of my broader claims.

In 'accordance with the present invention, there may be provided a condenser shell 2 of any desired construction, havin formed therein at some suitable point an inlet 3 for the vapor mixture to be condensed, and also being provided with a suitable outlet 4 from Ywhich condensate may be withdrawn to a suit- Aable point of `use. l l f vWhile the specific construction of the cona5 denser is relatively immaterial, the figure illustrates diaraml'natically a condenser provided. with a oating head 5 and with tubes 6 so a'rran d as to rovidea double pass con-- denser. ooling liquid may be supphed t0 100 thetubesthroughtheinlet 7 and after passage therethrough may be withdrawn from the apparatus through the outlet 8. The inlet and olfitlet may be formed in a header assemby 9 o If desired, bales 10 of any desired construction, length and arrangement may be provided within the shell of the apiaratus o r insuring a flow of' vapors an gases through the heat exchangerin a enerally longitudinal direction accomplishe by a series of successive transverse paths. v

At a int intermediate the vapor intake 3 and t e condensate outlet 4 theremay be provided a gas oiltake 11 which may comprise a single connection with the intertube or condensing space within the shell or which may comprise a series of longitudinally spaced connections such as indicated at 12. These connections may each communicate with -a se arate eva'cuating mechanism in theevent t e apparatus is to be operated at a y communicate withthe atmosphere in the event of an operation at atmospheric pressure, or they may be connected toy a common connection 13 as may be desired. In an event, a separate re lating valve 14 will be rovided for each ofgtllie oitakes whereby any esired oltake may be brought into use at will to the exclusion of the others.

For purposes of illustration it may be asf sumed that the valve controlling the oitake 12 is closed while the valve controlling the offtake 11 is open. With the heat exchanger in normal operation such as occurs in the handling of vapors resulting from the distillation of oils, at least partial condensation of the vapors will have beeny obtained Aby the time the have' traveled to a point adjacent the oitae 11. Some of the will therefore be drawn out at this point, to ther with some small amount of vapor, w ile the remalmng portion of the uncondensed vapor mixture will travel onwardly as indicated .byV

'- the arrows where condensation proceeds. In-

asmuch as there is no otakefor thisportion of the condenser, owever, gas remaining after the condensation of the vapors will aecumulate =in the portion below the oil'take 11, and as condensation rogressively continues,

the partial pressure ue to vapor [will gradpartial pressure due an desired construction as well un er-N Astood 1n the art.

pressure below atmospheric, or may separatedrawn fromA the condensate4 outlet 4, the

coolin being further effected by the contact o the condensate with the relatively cold tubes through which the circulating fluid is assed.

e point of gas oitake, therefore,ma be considered as dividing the vapor space o the Y l Aunit into a condensing zone and a cooling zone, the oiitake constituting either an imaginary or real division between these :two

zones. By placing the point ,of gas oil'take closer to the vapor inlet, the capacity of the condensing zone is correspondingly reduced, while the capacity of the cooling zone is increased. Sucha condition would enable the obtaining of condensate having relatively lower temperatures. 0n the other hand, by placing the point of gas oitake more remote from the vapor inlet, exactl the op site condition is effected and con ensate o relatively higher temperature results. The position of the gas off-take therefore, ma be varied in accordance with the amount o vapor .which it is desired to condense and the temperature of the condensate which it is desired to produce.A The present invention, as willbe apparent to those skilled in the art,

y contemplates the positioning of the gas oil'- take in accordance with the relation'which it is desired to produce between the condensin and cooling. This ,enables a single piece o apparatus to be eiectively utilizedrfor diferent operations, thereby 'minimizing the number of parts required for the commercial adaptation of the invention, withl a corresponding cheapening of the manufacturing costs by reason of the standardization of the ma'or elements of the apparatus. l

ertain advantages of the present invention arise from the provision of a heat exchanger so constructed as to provide a condensing zone and a Ycooling zone, and more particularly from an apparatus in which such zones are effectively produced by the posi- -tioning of a gas oitake intermediate the point of vapor inlet and condensate outlet.

Still other advantages vof the invention arise from the provision of a unitary condensing apparatus so constructed as to permit effective control of the condensation and cooling, together with a desired variation in either of these conditions.

V1. In a heat exchanger, a condensing zone, acooling zone', a lurality of `individually controlled gas oil'taes eiective intermediate said zones, and a condensate outlet for drain-- ing the condensatelevel substantially tothe .bottom of the cooling zone. 1 2. In a heat exchanr, a condensing zone, acooling zone, each o said zones comprising a combined vapor and gas space, andmeans for varying the eiective area of atleast one ofsaid zones. l' A 3. In u heat exchanger, a condensing.

a cooling zone, means for varying the eifective area of both of said zones, and a condensate 'outlet for draining the condensate level substantially to the bottom of the coollng zone. y

4. In a heat exchanger, a condensing zone, a cooling zone, said zones having a serial flow of vapor therethrough, a plurahty of gas ol'- takes located in 'stepped' relation in regard to the vapor and gas iow and dening said zones, and means effective at will for rendering any desired oiftake inoperative.

5. In a tubular heat exchanger, a condensin zone, a cooling zone, a plurality of gas o takes located in step ed relation in regard to the vapor and gas ow and dening said zones, and means `effective at will for rendering any desired olftake inoperative.

6. In the method of operating heat exchangers, the steps consisting of providing a vapor inletl and a condensate outlet, removing non-condensible gas at a point intermediate said inlet and outlet and at a distance lsubstantially spacedl therefrom to provide distinct condensing and cooling zones, and varying the :point of gas removal to vary the effectiveness of said zones.

7. In a heat exchanger, a condensing zone, a cooling zone, means for varying theefective area of at least one of said zones, and a condensate outlet for draining the condensate level substantially to the bottom of the cooling zone.

8. In the method of operating closed heat' exchangers, the steps comprising supplying a cooling medium thereto, delivering the fluid to be condensed, withdrawing vapor and noncondensible gases therefrom, and varying the point of withdrawal to vary the `condensate temperature.

9. In the method of operating closed heat exchangers, the steps comprising supplying a cooling medium thereto, delivering the fluid to be condensed, and controlling the `temperature ofthe condensate by increasing the partial pressure of the non-condensible gases in Contact therewith. p

10. In the method of operating closed heat exchangers, the steps comprising supplying a cooling medium thereto, delivering the fluid to be condensed, controlling' the temperature of the condensate by increasing the partial pressure of the non-condensible gases in contact therewith, and varying the partial pressure of the non-condensible gases in contact vtherewith to vary the.condensate temperature.

In testimony whereof I have hereunto set my hand.

' LAWRENCE M. FORNCROOK. 

